1. Field of the Invention
The invention relates to ratchet wrenches and more particularly to an easy to assemble ratchet wrench.
2. Description of Related Art
A socket wrench is a wrench with interchangeable heads called sockets that attach to a fitting on the wrench, allowing it to turn different sized bolts and other fasteners. The most common form is a hand tool popularly called a ratchet consisting of a handle with a ratcheting mechanism built in, so it can be turned using a back-and-forth motion in cramped spaces. A socket has a cup-shaped fitting with a recess that grips the head of a bolt. The socket snaps onto a male fitting on the handle. The handle supplies the mechanical advantage to provide the torque to turn the socket. The wrench usually comes in a socket set with many sockets to fit the heads of different-sized bolts and other fasteners. The advantage of a socket wrench is that, instead a separate wrench for each of the many different bolt heads used in modern machinery, only a separate socket is needed, saving space.
A conventional ratchet wrench comprises a handle having a head on one end, the head including a hole for rotatably receiving a drive member, a compartment defined in a periphery defining the hole of the head, and a pawl received in the compartment; an anchor mounted in the compartment and including a fulcrum in contact with a wall defining the compartment, and a pair of protrusions on one end for alternately engaging with teeth of the drive member so that the anchor sways but does not slide in the compartment; and a biasing member anchored between the other end of the anchor and a side of the pawl wherein the pawl has a toothed face for engaging with the teeth of the drive member so that when the handle turns idly, the pawl is moved toward the anchor and compresses the biasing member that returns the pawl to a position for engaging with the drive member.
However, a number of drawbacks of the ratchet wrench have been found. In detail, the pair of protrusions of the anchor alternately engaged with the teeth of the drive member during idle rotation of the handle may wear the teeth of the drive member. Further, the anchor may be stuck in the compartment during idle rotation of the handle since there is no means to limit movement of the anchor in the compartment when the anchor is subject to a force exerted by the pawl. Further, the location of the anchor affects operation of the wrench. More specifically, if the swayable anchor is adjacent to the drive member, the swaying angle for the anchor could be too small, and if the swayable anchor is distal the drive member, the swaying angle for the anchor could be too large. This can increase difficulty in assembly of the ratcheting wrench. Further, when the handle is subject to vibrations and/or hammering, the anchor may move to a position prohibiting swaying movement of the anchor.
Thus, the need for improvement still exists.